Adjustable strut



2 Sheets-Sheet 1 J. J. M CARTHY ADJUSTABLE STRUT I INVENTOR. John J.McCarthy V, V flcSENT plain. mg

Fi led Oct. 23, 1965 Feb. 6, 1968 NM ANN J. J- M CARTHY ADJUSTABLE STRUTFeb. 6, 1968 2 Sheets$heet 2 Filed Oct. 23, 1965 3m 6% d f? g a:

INVENTOR John J. McCarthy .m I B HCIENT United States Patent 3,367,689ADJUSTABLE STRUT John J. McCarthy, Broolrfield, Conn. NorcoIncorporated, P.O. Box 405, Georgetown, Conn. 06829) Filed Oct. 23,1965, Ser. No. 503,023 7 Claims. (Cl. 287-58) ABSTRACT OF THE DISCLOSUREAn adjustable strut comprising a pair of tubular relativelylongitudinally movable telescoping members one of which has a pair ofmatched, notched longitudinal slots coextensive with each other. Theother member has locking dogs which ride in the slots and which aremovable laterally of the memberto enable them to occupy pairs of notchesin the slots. A longitudinally movable release rod is mechanicallycoupled to the locking dogs to actuate the same for movement into andout of the notches. The release rod is carried in the strut member whichhas the dogs, and is accessible at one end of the member for manualactuation.

This invention relates to braces, struts and the like, and moreparticularly to multi-part struts or braces which are adjustable as totheir lengths.

Heretofore, two-part adjustable struts were proposed wherein a singleretractable locking piece or dog on one part engaged a cooperableabutment on the other part to lock the parts to each other. Under severestress such struts could fail at the location of the locking, due to thesmall areas and sections which were there involved.

The above disadvantages of prior adjustable struts of relatively lightconstruction are obviated by the present invention. This is accomplishedby the provision of multiple locking dogs, specifically a pair of saiddogs, whereby double the areas and sections exist at the point oflooking. Thus there is much less likelihood of failure of the strutunder severe working stresses.

-Therefore an object of the invention is to provide a novel and improvedmulti-part adjustable strut which is especially sturdy and rugged whileat the same time having a relatively light total or aggregate weight.

Another object of the invention is to provide an improved multi-partadjustable strut as above set forth, which is quick and easy to adjust,and which will reliably stay in its various adjusted positions againstthe action of substantial disrupting forces.

A still further object of the invention is to provide an improvedadjustable strut or brace as characterized, which is simple inconstruction, involving relatively few parts of giedkind that can beeconomically fabricated and assem- A feature of the invention resides inthe provision of an adjustable multi-pa-rt strut in accordance with theforegoing, which is particularly adaptable to a wide variety ofapplications.

Still another object of the invention is to provide an improvedadjustable strut as outlined, which may be operated or adjusted fromeither a point beyond one end of the strut or else from a pointintermediate the ends.

Another feature of the invention resides in the provision of an improvedadjustable strut of the type indicated, which is capable of a pluralityof adjusted positive positions.

A further object of the invention is to provide a strut in accordancewith the foregoing, wherein a very large number of adjusted positions ispossible, involving minute increments or adjustment.

Still another feature of the invention is the provision of an adjustablestrut wherein the clamping or locking 3,367,689 Patented Feb. 6, 1968"ice means or member is wholly enclosed and protected from adverseexternal conditions.

Other features and advantages will hereinafter appear.

In the drawings accompanying this specification, similar characters ofreference are used to designate like components throughout the severalviews, in which:

FIG. 1 is a side view of an adjustable strut made in accordance with theinvention.

FIG. 2 is an axial sectional view of the strut of FIG. 1.

FIG. 3 is a fragmentary detail in elevation, of the cam portion of therelease bar of the strut.

FIG. 4 is an end elevational view of the cam portion shown in FIG. 3.

FIG. 5 is a side view of the roller locking member utilized with the camshown in FIGS. 3 and 4.

FIG. 6 is an axial fragmentary sectional view of an adjustable strutillustrating another embodiment of the invention.

FIG. 7 is a fragmentary view partly in axial section and partly in sideelevation of an adjustable strut constituting another embodiment of theinvention, wherein the locking member or means is Wholly enclosed andprotected from adverse external conditions.

FIG. 8 is a transverse section, taken .on the line 3--8 of FIG. 7.

FlG. 9 is a fragmentary view partly in axial section and partly in sideelevation, illustrating an adjustable strut constituting yet anotherembodiment of the invention.

Referring first to FIGS. 1-5, the adjustable strut as illustratedtherein comprises a pair of tubular telescoping members 10, 12 havingmeans for attachment respectively to structural parts whose relativepositions are to be controlled or varied. For example, the member 12 hasa threaded bore 14 receiving a screw or bolt 16 by which it is securedin end-abutting relation to a supporting wall or plate 18. The tubularmember 10 has external screw threads 20 and. an hexagonal flange 22 bywhich it may be threaded into a structure or wall 24.

In accordance with the present invention, the tubular strutmember 10 isprovided with a pair of longitudinal slots 26, 28 which are coextensivewith each other and arranged generally in diametrically oppositelocations. The slots 26, 28 have notches disposed in similar locationsalong their lengths. In FIG. 1 the slot 26 is shown as having notches30, whereas in FIG. 2 the slot 28 is seen to have similar notches 32.

The tubular strut member 12 has a pair of transverse slots 34, 36 whichare respectively adjacent the longitudinal slots 26, 28. Carried in thefour slots 26, 23, 34, 36 is a locking device or member 38, see FIGS. 1and 5, said locking member being movable in the transverse slots 34, 35between positions occupying the notches of the longitudinal slots (asseen in FIGS. 1 and 2) and other positions which are removed from thesaid notches. The occupied positions of the member 38 effect a lockingof the telescoping members 10, 12 in different: adjusted positions,whereas the removed positions of the locking rnember 38 effect anunlocking of the telescoping tubular members for enabling relativeadjustment to be had.

Referring to FIG. 5, the locking member 33 has a portion 40 of reduceddiameter intermediate its end portions 42, 44 (hereinafter also calledlocking dogs), said member being of cylindrical cross section as Well beseen in FIG. 1.

For controlling the movement of the locking member 38 there is providedin the tubular strut member 12 a release bar 46 which has a cam portion48 engageable With the middle portion 40 of reduced diameter of themember 38. As seen in FIG. 3, the cam portion 455 has cam surfaces 50and 52 which act on the locking member 38 to shift the latter in thelateral slots 34, 36 between the locking and releasing positions.

Referring to FIG. 2, the central portion 40 of the locking member 38 isengaged with a straight surface 54 of the cam portion 48, by whichlateral movement of the locking member is prevented in its lockingposition. When the release bar 46 is shifted to the right from theposition shown in FIGS. 1 and 2, the camming edge 50 will shift downwardthe locking member 38, removing the dogs 42, 44 respectively from thenotches 30, 32 of the slots 26, 28. In consequence, the telescopingstrut members 10, 12 will be released from each other and capable ofrelative movement, as permitted by the absence of the dogs 42, 44 of thelocking member 38 from the notches 30, 32.

Spring means are provided, comprising a compression coil spring 58engaged with washers 60 on the release bar 46 and also engaged with aninternal shoulder 62 in the member 12, thereby to normally bias therelease bar 46 to the leftmost locking position as seen in FIG. 2. Astop collar 64 fastened in the end of the member 12 limits the leftwardmovement of the release bar 46.

An operating device is provided for shifting the release bar to theright against the action of the spring 58, such device comprising inFIGS. 1 and 2 a handle 66 which is affixed to the collar 54 and thus tothe strut member 12, and a finger-engageable end portion 68 of therelease bar 46, which extends through the center of the handle 66 and ismovable therein.

It will now be understood, with the construction as illustrated in FIGS.1 and 2, that an adjustable positioning is possible of the parts 18 and24 with respect to each other. By depressing the button 68 and pullingor pushing on the handle 66, the structural part 24 may be moved eitherfurther away from or closer to the part 1-8. When the button 68 isreleased, continued movement of the handle 66 and member 24 will resultin the locking member 38 snapping into the next two notches 30, 32,whereby the strut 10, 12 will be secured in a new adjusted position,maintaining the members 18 and 24 likewise adjusted.

Another embodiment of the invention is illustrated in FIG. 6, whereinthe release is effected at a place intermediate the ends of theadjustable strut in contra-distinction to the embodiment of FIGS. 1-5wherein the release is effected from a point beyond one end of thestrut.

In FIG. 6, like parts have been given similar numbers but with thesuffix a. As shown, the tubular strut member a has a pair oflongitudinal oppositely disposed slots 70 through which a pin 72extends. The pin 72 is secured to an operating sleeve 74 which isslidable on the strut part 10a, and said pin also passes through the endportion 68a of the release bar 46a. With this construction, movement ofthe release sleeve 74 from left to right as viewed in FIG. 6 will shiftthe release bar 46a from left to right, causing the locking member 38ato be shifted out of the notches 38a and fully into the slot 26a. Thiswill release the two strut parts 10a, 12a for relative adjustingmovement. Upon release of force from the sleeve 74, continued movementof the strut parts 10a, 12a will result in the locking member 38abecoming nested in another one of the notches 30a, thereby locking thestrut parts in a different adjusted position.

It will now be understood from the foregoing that I have provided animproved adjustable strut construction wherein the locking member 38 (or38a) is positively retained in the notches 30, 32 (or 30a or 32a)thereby reliably securing the strut members in their various adjustedpositions. The strut is characterized by great strength and sturdiness,and by reliability in its operation while at the same time the releaseof the locking means for effecting adjustment of the strut may be easilyand quickly effected. Relatively few parts are involved, such partsbeing capable of economical fabrication and assembly. Adjustment of thestrut may be effected either from a point beyond the end as in FIGS.1-5, or else from a point intermediate the ends as in FIG. 6.

Another embodiment of the invention is illustrated in FIGS. 7 and 8. Inthis embodiment, the clamping or locking means is wholly enclosed in thestrut, thereby being protected from adverse external conditions such asdirt, dust and other foreign matter, the direct action of water, etc.

In FIGS. 7 and 8, components which are similar to those alreadydescribed previously have been given like characters. The strut member12 having transverse slots 34, 36 carries the release bar 46 whichterminates in the release button 68. The handle 66 is connected with thestrut member 12, said member being slidably carried in an outer strutmember 10b which is threaded into the supporting structure 24. Therelease bar 46 has the cam portion 48 which, in this embodiment of theinvention, engages the yoke portion 76 of a U-shaped locking member 38b.The member 3812 occupies the transverse slot 34, 36 of the strut member12 and has an external peripheral surface forming parts of a circle.

The strut member 10b has a series of locking shoulders extendinglongitudinally thereof, formed by a plurality of internal annulargrooves 78 any one of which may be occupied by the locking member 38b.In FIG. 7, the member 38b is shown as occupying the right-most one ofthe grooves 78 of the strut member 1011. This position locks the strutmembers 10b and 12 in an adjusted relation. To shorten the adjustablestrut, the button 68 is depressed, this resulting in a retraction ordownward movement of the locking member 38 as viewed in FIGS. 7 and 8.Such movement will remove the locking member from the internal groove inthe strut part 10b which it has occupied, and will Withdraw the lockingmember 38b so that it is flush with the exterior surface of the strutmember 12. When this occurs, the member 12 may be shifted from right toleft, and upon release of the button 68, the locking member 38b willextend or move upward to snap into one of the other grooves 78, therebylocking the strut in a new, adjusted position.

It will be noted that the locking member 38b and the grooves 78 arewholly concealed and enclosed, whereby they are protected from theaction of dirt, dust, grit, water and other foreign matter. Accordingly,a reliable and free-acting release and locking of the strut may beexpected with this construction, under adverse conditions of use.

Yet another embodiment of the invention is illustrated in FIG. 9,wherein the strut member 12 carries in its transverse slots 34, 36 aU-shaped locking member 380 having screw thread formations on its arms,specifically on the outer, circular peripheral portions thereof. Thestrut member 10c has an internal helical screw thread 80, which ispreferably chased in the member by a suitable tap. The thread formationsof the locking member 380 will mate with the internal screw thread 18whereby the strut members 12 and may be locked in a very large number ofdifferent positions, representing minute increments or adjustments.While a V-shaped thread formation is shown, it will be understood that asquare or Acme thread formation may be used instead, where a more securelocking action is required.

The embodiment of FIG. 9 also represents a wholly enclosed and protectedconstruction, as regards the locking member or means. Whereas arelatively course adjustment is had with the embodiment of FIGS. 7 and8, a very fine adjustment is possible with the embodiment of FIG. 9.

Variations and modifications may be made within the scope of the claims,and portions of the improvement may be used without others.

I claim:

1. An adjustable strut comprising, in combination:

(a) a pair of tubular, telescoping members having means for attachmentrespectively to structural arts whose relative positions are to becontrolled,

(-b) one of said members having a pair of longitudinal slots coextensivewith each other,

(c) said slots having notches disposed at similar locations in theirlengths,

(d) said other member having a pair of transverse slots respectivelyadjacent said longitudinal slots,

(e) a locking member disposed in said transverse and longitudinal slots,said locking member including dogs which are movable in said transverseslots between positions occupying the notches of the longitudinal slotsand positions removed from said notches,

(f) said occupied positions of the dogs effecting a locking of thetelescoping member in adjusted positions and said removed positionseffecting an unlocking of the members for relative adjustment,

(g) a release bar slidable in said other member and having a camengageable with the locking member to shift the dogs thereof in saidlateral slots,

(h) spring means biasing the release bare to a position in which thelocking dogs are shifted to their notchoccupying position, and

(i) an operating device for shifting the release bar against the actionof said spring means.

2. An adjustable strut as in claim 1, wherein:

(a) the locking member comprises a pin having a portion of reduceddiameter intermediate its ends, the end portions of the pin comprisingthe said dogs,

(b) said cam engaging the portion of reduced diameter of the lockingmember, and

(c) the two dogs of the locking member being disposed in said transverseslots and projecting at all times beyond the exterior of said othertubular member.

3. An adjustable strut as in claim 2, wherein:

(a) the operating device comprises a sleeve slidably mounted on saidother tubular member.

4. An adjustable strut as in claim 2, wherein:

(a) the operating device comprises a handle rigid on said other tubularmember, and a movable manually operable pin in the handle, connectedwith said release bar.

5. An adjustable strut comprising, in combination:

(a) a pair of tubular, telescoping members having means for attachmentrespectively to structural parts whose relative positions are to becontrolled,

(b) one of said members having locking shoulders disposed longitudinallythereof, said shoulders comprising circumferentially-spaced rows ofabutment surfaces, said rows being coextensive With each other,

(c) said other member having a pair of transverse slots adjacent saidrows of abutment surfaces of the shoulders,

(d) locking dogs disposed respectively in said transverse slots, saidlocking member being movable therein between laterally extended andlaterally retracted positions wherein they are respectively engaged withand disengaged from said abutment surfaces of the shoulders,

(e) said extended and engaged positions of the dogs eifecting a lockingof the telescoping members in adjusted positions and said retractedpositions of the dogs effecting an unlocking of the telescoping membersfor relative adjustment,

(f) a release bar slidable in said other member and having a cam coupledto the locking dogs to shift the latter in said lateral slots,

(g) spring means biasing the release bar to a position in which thelocking dogs are shifted to their extended positions, and

(h) an operating device for shifting the release bar against the actionof said spring means.

6. An adjustable strut as in claim 5, wherein:

(a) said one member has internal grooves the sides of which comprisesaid abutment surfaces,

(b) said locking dogs comprising the arms of a U- shaped piece, saidarms being receivable in said grooves.

7. An adjustable strut as in claim 6, wherein:

(a) the internal grooves are formed by a helical internal screw thread,

(b) said arms of the U-shaped piece having thread segments engageablewith the internal screw thread,

References Cited UNITED STATES PATENTS 1,028,126 6/1912 Meredith 287-582,329,932 9/1943 Nelson 287-58 2,884,270 4/1959 Carlberg 28758 2,932,0474/1960 Johnston 287-58 3,184,816 5/1965 McCarthy 287-58 CARL W. TOMLIN,Primary Examiner.

W. L. SHEDD, Assistant Examiner.

